Electron tube apparatus



Dec. 18, 1962 R. L. WALTER ETAL 6 SheetsSheet 1 INVENTORS James C. Filmer Richard L. Walter ATTORNEY Dec. 18, 1962 R. L. WALTER ETAL 3,069,590

ELECTRON TUBE APPARATUS Original Filed June 14, 1955 6 Sheets-Sheet 2 IE'IE E.

JNVEJYTOR. James C. F :lmer

y Richard L. walre 2 x;

Af rorney 6 Sheets-Sheet 3 INVENTORS James C. Filmer Richard L, Walter ATTORNEY Dec. 18, 1962 R. WALTER ETAL ELECTRON TUBE APPARATUS Original Filed June 14, 1955 3 I I w a I liillaak lum H s rvw lnn "a" v I \I \I Ir} MW I N ..1|J "a A M \z g Q w I Q v r A v l 4 3 H w M H w w 1 6 4 3 5 4 2 5 aw 5 M ,3 6 0 3 0 6 3 E 6 6 6 9 I a a w r Dec. 118, 1962 R. L. WALTER ETAL 3,069,590

ELECTRON TUBE APPARATUS Original Filed June 14, 1955 6 Sheets-Sheet 4 INVENTORS James C. Filmer w W W T T T 1 79 1 m a w 7 \/8 4 5/ 2 6 4 7 Z 4 0 W W MN m 9 9 5 T1 7 m! m z 7 x M 44. i if r T WW NWQTY T 5 1 r .ltll A 1 \V l 1, li. nfi s E w w w Richard L. Walter ATTORNEY Dec. 18, 1962 R. L. WALTER ET AL ELECTRON TUBE APPARATUS 6 Sheets-Sheet 5 Original Filed June 14, 1955 m D mam W W w M 5 r y WW /I\ ATTORNEY Dec. 18, 1962 R. L. WALTER ETAL 3,069,590

ELECTRON TUBE APPARATUS Original Filed June 14, 1955 6 Sheets-Sheet 6 Nam M mL m m m JR ATTORNEY 3,tl69,590 ELETRON TUBE APPARATUS Richard L. Walter and James C. Filmer, Palo Alto, Calif., assignors to Varian Associates, San @arios, Calif, a corporation of California Original application June 14, 1955, Ser. No. 515,327, new Patent No. 2,944,187, dated July 5, 1966. Divided and this application Aug. 5, 1959, Ser. No. 831,777

4 Claims. (til. 315-548) This invention relates, in general, to electron tube apparatus and, in particular, to novel electron tube apparatus of the type employing cavity resonators such as, for example, high power klystron tubes utilized in systems found in radar, navigation beacons and linear accelerators, etc. This application is a divisional application of pending application Serial No. 515,327 filed June 14, 1955, for Electron Tube Apparatus, now U.S. Patent 2,944,187, issued July 5, 1960.

In the art of high frequency amplification, for example, that range of frequencies between 2500 and 4000 mc., there has been lacking a pulsed amplifier that would provide high gain, that is, 55 db or over; high power, that is l megawatt or more with an average power of 2 kw., at the same time combining reliability and long life (1090 hours) with ease of operation.

Accordingly, it is the object of this invention to provide a novel high power, high gain, electron tube apparatus offering ease of operation, long life, and electrical stability.

One feature of this invention is a novel system for remote tuning of the cavity resonators thereby facilitating front panel operation of the apparatus.

Other features and advantages of this invention will become apparent from a perusal of the specifications taken in connection with the accompanying drawings wherein,

FIG. 1 is an elevational view partly in section showing the assembled electron tube apparatus of this invention,

FIG. 2 is a fragmentary side elevation of the structure of FIG. 1,

FIG. 3 is a fragmentary end view of a cavity resonator and associated parts,

PEG. "4 is an enlarged part sectional view taken along line i4 of FIG. 2 looking in the direction of the arrows,

FIG. 5 is an enlarged cross sectional view taken along line 55 of FIG. 2 looking in the direction of the arrows,

FIG. 6 is a sectional view taken along line 66 of MG. 2 looking in the direction of the arrows, and

FIG. 7 is an end view of the apparatus looking in from the collector end.

The construction of the novel electron tube apparatus will now be described followed by a description of the operation and function of the apparatus.

Referring now to FIG. 1, the novel tube apparatus comprises a cathode structure 1, resonators 2, 3, 4 and 5 and a collector assembly 6. Signal energy to be amplified is supplied tothe first resonator 2 via a concentric line input 7 and amplified in successive resonators 3 and 4'. The amplified signal is extracted from the output resonator 5 and propagated to the load through waveguide 8. The cathode is immersed in an oil bath contained within a tank 9 to prevent arc-overs in the external cathode region. Surrounding the resonators is an electrical coil 11 for creating a strong magnetic field to confine the electron beam in the resonator region.

Tuning of the cavity resonators is accomplished through a plurality of tuning plungers 57 (FIGS. 2, 4 and 6) movable within the cavity resonators and extending outwardly thereof through an aperture in the resonator wall.

Secured to the inward end of the tuning plunger 57 is a thin rectangular flexible metal diaphragm 58 of a good electrical conducting material, for example, copper plated Monel. The flexible diaphragm is secured to the cavity resonator wall on two opposite edges only, the remaining two edges being slightly spaced from the resonator walls. interposed between the outside wall of the cavity resonator and the outward extremity of the plunger extension is a bellows 59' which envelops the tuning plunger. The bellows is sealed at one end to the plunger and at the other end to the outer wall of the cavity resonator thereby maintaining vacuum integrity within the cavity while at the same time allowing movement of the tuning plunger 57.

Secured to and surrounding the outward extremity of the tuning plunger is a cup-shaped tuning rack support 61 having attached to its outward wall in diametrically opposed relation two smooth rectangular bars, tuning rack support guides 63 (FIGS. 3 and 5). Similarly mounted on said tuning rack support 61 and ninety degrees to said guides 63 is a toothed bar, tuning rack 62. Mounted on the outward side of the cavity end wall and extending outwardly adjacent the tuning rack support guides 63 is tuner slide block 64- having two rectangular recesses cut therein (FIG. 3) and fitted with bearing liners 60 as of, for example, tetrafiuoroethylene resin to receive the tuning rack support guides 63 slidable therein. Actuating the tuning plunger through coaction with tuning rack 62 is a pinion 65 mounted on one extremity of a tuning actuating rod 66 which extends through an opening in and is held in position by a pinion mount 67. Operating pinion 65 and upwardly extending through apertures suitably provided in the stiffener plates 55', actuating rod 66 (FIG. 2) further extends through output pole piece 54- and terminates in a gear case 68 (FIG. 7). Within the gear case and rigidly afiixed to the tuner actuating rod is a toothed worm gear 69. Interposed between the toothed worm gear and the output pole piece is a rectangular gear case mounting plate 71 (FIGS. 5 and 3) having an aperture therein, the inner surface of the aperture forming a bearing surface for tuner actuating rod 66. Enveloping the toothed worm gear 69 (FIG. 7) is the rectangular cup-shaped gear case 68 having an opening 72 in the side outward of the tube (FIG. 5). Rotatable within the gear case 68 is a worm shaft 73 positioned to cooperate with said toothed worm gear 69 said worm shaft extending outwardly of the gear case 68 and deriving bearing support from the inner surface of the side opening 72. Remote actuating means may be coupled to the worm shaft 73 to effectuate remote tuning of the cavity resonators. Remote tuning is often desirable in variable frequency tubes. When installed in a system gaining access to the tube may be difficult. Moreover, in some high power applications X-ray radiation from the collector can be avoided by tuning from a remote station.

Output energy (FIG. 7) is extracted from the output cavity resonator 5 through output iris 74. Whence the energy is propagated through waveguide 8 outwardly and upwardly through output window 75 (FIG. 7) to the load.

In operation electrons are emitted from the cathode focused into a beam by the focusing electrode 36 and accelerated through the drift tube. The signal to be amplified is fed into the input cavity :2 where the beam is velocity modulated. As the modulated beam travels down the drift tube it is further modulated by the intermediate bunching cavities 3 and 4, while within the drift tube the beam is confined in diameter against forces tending to spread the beam, such as space charge forces, by the magnetic field lines supplied by the foscusing coils 11, said lines of flux being parallel to the drift U tube in this region. The output cavity extracts electromagnetic energy from the modulated beam and said energy is then coupled out of the output cavity through iris 74 and propagated through waveguide 8 and window 75 to the load. Tuning of the tube is obtained by a movable wall type tuning plunger which is movable within the resonator by rotation of worm shaft 73 which operates upon actuating rod 66 which in turn cooperates through pinion 65 to cause tuner rack support and attached plunger and diaphragm to move in and out of the cavity thereby changing the resonant frequency of said cavity.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an electron tube apparatus a tuner assembly including, an evacuated cavity resonator adapted for electromagnetic interaction with a beam of electrons passable therethrough, a tuning plunger movable within said cavity resonator for changing the resonant frequency thereof, said plunger having an extension extending outwardly of said cavity resonator through an aperture in the side wall thereof, an extensible bellows sealed in a gas tight manner at its ends to said tuning plunger and the side wall of said cavity resonator for allowing movement of said tuning plunger without destroying the vacuum integrity of said cavity resonator, a tuning rack support member carried outwardly and along the side of said plunger extension and fixedly secured thereto, said rack support being longitudinally coextensive with a substantial portion of said bellows whereby the length of said plunger extension is minimized, a rack carried longitudinally of said rack support member, and a pinion engaging said rack for driving said plunger Within said cavity resonator for tuning thereof.

2. The apparatus according to claim 1 including a tuner guide member carried outwardly and along the side of said plunger extension and fixedly secured thereto, a guide block having a recess therein for slideably mating with said tuner guide member to guide said tuning plunger, said guide block being fixedly coupled to said cavity resonator.

3. The apparatus according to claim 2 wherein said tuner guide member is disposed within a plane substantially at 90 to the plane containing said rack.

4. The apparatus according to claim 1 wherein said tuning rack support member comprises a cup-shaped member carried from said plunger extension with the side walls of said cup-shaped rack support being disposed substantially coaxial with, externally of, and in surrounding relationship with said bellows.

References Cited in the file of this patent UNITED STATES PATENTS 2,106,768 Southworth Feb, 1, 1938 2,106,769 Southworth Feb. 1, 1938 2,304,186 Litton Dec. 8, 1942 2,342,897 Goldstine Feb. 29, 1944 2,807,746 Gardner et a1. Sept. 24, 1957 

